Machine for distributing concrete



Feb. 19 1924.

E. H. LICHTENBERG MACHINE FOR DISTRIBUTING CONCRETE Original Filed July19 1920 5 Sheets-Sheet l H I J j E i m .7

E. H. LICHTENBERG MACHINE FOR DISTRIBUTING CONCRETE Original Filed July19. 1920 5 Sheets-Sheet 2 Feb. 19

E. H. LICHTENBERG MACHINE FOR DISTRIBUTING CONCRETE Original Filed July19 1920 5 Sheets-Sheet 5 iilllllllllll lll \II L llmlhlllill IIHIIIIHI.

Feb. 19 1924. Re, 15,768

E. H. LICHTENBERG MACHINE FOR DISTRIBUTING CONCRETE Original Filed July19, 1920 5 Sheets-Sheet 4 Feb. 19 1924.

E. H. LLCHTENBERG MACHINE FOR DISTRIBUTING CONCRETE Original Filed July19, 1920 5 Sheets-Sheet 5 Reisaued Feb. 19, 1924.

UNITED STATES PATENT OFFICE.

ERICK H. LICHTENBERG, OF MILWAUKEE, WISCONSIN, ASSIGNOR, BY MIESNEASSIGN- MENTS, TO KOEHBING COMPANY, .OF MILWAUKEE, WISCONSIN, ACORPORATION OF WISCONSIN.

Original No. 1,411,217, dated March 28, 1922, Serial No. 997,431, filedJuly 19, 1920.. Application for I reissue filed November 17, 1923.Serial No. 675,390.

ments and the like, there is commonly used as the most expeditious andeconomical method of distributing the concrete or mixed aggregates ofwhich the pavement is composed, a machine which comprises, generallyspeaking, a combined mixer and boom and bucket distributing means. Thismachine, ordinarily known as the -Koehring paver, embodies a portableplant which includes the concrete mixingdrum and customary appurtenantcontrol mechanisms, together with the boom and bucket attachmentoperated from the same power as used for the mixing machine andcontrolled by the same operator.

The chief desideratum of the present invention is the reduction of thelabor 'expense involved in effecting the distribution of the concrete'ormixed aggregates as incident to the operation of a paving machine of theclass above described. By this machine the aggregates are commonlydumped in a pile upon a surface or sub-grade being paved, there to bedistributed by laborers of whom two or more will be used for thespreading of the aggregates after they have been deposited upon thesurface of the sub grade. In the practical embodiment ,of a machine ofthis character, I have so designed the distributing bucket oi the boomand bucket device previously referred to, and have so improved thecontrolling means for the operation of said bucket as to cause theaggregates of concrete delivered from the sald receptacle to bedeposited upon the sub-grade surface in a stream-like manner and of a.predetermined thickness or depth, variable on account of the provisionof special means for this particular purpose.

That is to say, instead of depositing the aggregates in piles to besubsequently spread by' expensive labor, y o m and bucket mechanism asnow improved in comparison with the mechanism of my previous LettersPatent No. 1,141,470 and No. 1,113,661 issued June 1, 1915, and'October13, 1914, respectively, permits the concrete to be delivered to thesurface on-which it is to be laid in a ribbon-like stream ofapproximately rectangular formation in cross section, the depth orthickness of the layer of aggregates deposited being susceptible ofvariations according to the specifications of the particular contractgoverning the work. This constitutes also my novel method.

For the accomplishment of the foregoing I have redesigned the bucket andboom a1:

rangements and the openable bucket door mechanism of my previous patentsabove identified. V I

In addition to the foregoing, among other objects of my invention, havebeen the simplifying of the driving mechanism utilized for causing thebucket to traverse the boom by which the distribution of the concreteover a relatively large area may be performed; the provision of a morepositive driving mechanism for the purpose just outlined; and theimprovement of certain knock-out or clutch neutralizing devices, certainof which have been heretofore proposed by me for automaticallydiscontinuing the traverse of the bucket upon thev boom,

this being timed in respect to both the outward and the inward movementsof the bucket relatively to the mixing machine by which the concrete issupplied thereto.

In the present design of boom and bucket distributing mechanism there isalso proposed an improved device for causing the swinging of the boom ina horizontal plane to efi'ectthe proper distribution of the aggregateson different portions of the subgrade. This feature of my invention isof importance and involves the worm and worm gear contrivancesoriginally proposed in the Letters Patent Reissue No. 13,617, is-

sued September 16, 1913, to Philip A. Koehring, said patent covering thebasic machine improved by the features of my Let-' tors Patenthereinbefore designated. In the operation of the worm and worm gear boomturning means, there has been a tendency heretofore to cause locking ofthe engaged worm and worm gear contrivances, owing to the momentum ofthe boom once the horizontal movement is imparted thereto. I merelymount my worm in a resilient manner as regards end-wise moving, inrespect to the engaged worm ar, and in this way eliminate thepossibility of the disadvantageous locking of the parts as referred to,at the same time. rendering more easy the operation of the boom by saidparts manually in respect to initiating as well as sto pin said boommovement.

. fl 1 comprehension of the improvements of this invention will be hadupon I an understanding of the machines of the Letters Patent reviouslyset forth herein in connection with the following description and theaccompanying drawings in which Figure 1 is a slde view showingparticularly the boom and bucket attachment as designed with the presentimprovements, dotted lines indicating in a general way the adjacent endportion of the mixing machine more particularly the automatic stopomitted.

upon which the boom and bucket mechanism is mounted.

Figure 2 is a fragmentary view showing mechanism at opposite ends of theboom or cooperation with the driving gearing to render the laterinactive at proper times.

Figure 3 is a view looki toward the delivery or discharge end 0 themixer and bringing out more clearly the controllin lever and clutchshifting mechanism and a jacent driving mechanlsm above theinner end ofthe boom.

' Figure 4 is a vertical sectional view through the boom and lookingtoward the outer side of the bucket, bringing out more 'fully themounting of the carriage on the boom and bucket-door closing device.

Figure 5 is a plan view showing primarily the parts illustrated in Fig.1, the bucket and certain of the parts beneath the boom being Figure 6is, a plan view bringing out clearly the worm and worm'gearturningdevice as improved, also the bumper cooperative with the carriage tolimit the inward movement of the bucket on the .boom.

Figure 7 is a vertical sectional view taken about on the line 7-7 ofFig. 2.

Figure 8 is a similar sect on taken about on the line 88 of Fig. 2.

Figure 9 is a vertical section taken through a portion of the carriageshowing the shuttle or slide of the trip ing device.

Figure 10 is a plan view 0 the sameineluding a trip member.

Figure 11 is a section on the line 1111 of Fig. 10.

Figure 12 is a front view showing more clearly the windingdrum of thedriving mechanism.

Figure 13 is an enlar ed view showing more clearly the adjustab 0 stopon the carriage; and

Figure 14 is a perspective view showing more clearl the arrangement ofthe lever arms and links of the clutch shifting and knock out devices.

Referring to the drawings in which the same reference characters areused to desig nate corresponding parts in difi'erent views, and'describing the improvements hereof in detail, A denotes the portion ofthe mixing drum of themixing machine illustrated in conjunction with theboom and bucket mechanism, B the'frame work or main machine structure,and said drum A is rotatably operated in a well known manner by toothedgear rings C carried by the drum A, (see Figure, 5). The boom and bucketmechanism embodies as its primary features the boom 1 and the bucket 2,the latter spaced from the ground, power operated, and being normallynon-discharging in its body construction.

The driving mechanism by means of which the bucket is caused to traversethe boom 1 comprises a pair of shafts 3 and 4 having pinions at one endmeshing with the gearring 0 of the drum A whereby motion is transmittedconstantly to the shafts while the drum A is in operation. The shafts 3and 4 are equipped with normally idle bevel gears 5 and 6 respectively,adapted to be operatively connected to turn with said shafts by means ofclutches 7 and 8 respectively. The bevel gears 5 and 6 cooperate withthe winding drum 9 formed with a spirally grooved winding surface, saiddrum having at opposite ends large bevelv gears 10with which the gears 5and 6 mesh. The opposite ends 11' and 11 of an operating cable 11 windaround the drum 9in opposite directions, and have the extremitiesthereof fixedly attached to the drum at places shown best in Fig. 12 ofthe drawings. The said cable 11 extends from the end portion ll downunder a sheave 12 journaled on top of the boom 1 thence outwardly alongthe boom around a sheave 13 at the outer extremity of said boom. Fromthe sheave 13 the cable 11 is trained inwardly along the boom adjacentto its under side, said cable passing thence upwardly over a sheave 14located adjacent to the point of pivotal support of the boom 1. Atthispint the cable 11 has its end 11 port intermediate the boom and theframe work of the mixer.

To operate the clutches 7 and 8 a rocker lever 17 (see Figs. 3 and 5) isemployed, the same being equipped with shifting forks and being mountedupon a vertical shaft 18, seen best in Fig. 3. The shaft 18 has amainhand lever 19 connected with its lower end' and this lever isoperable to alternately render the clutches 7 and 8 active for effectingreverse movements of the drum 9 and cable 11 or to maintain the clutches7 and 8 in neutral positions.

The reverse operation of the drum 9 is effective to cause reversemovement of the bucket 2 relative to the boom 1 by interconnectionsbetween the cable 11 and the car riage 20, which interconnections arevery similar to those set forth in my previous Patent No. 1,141,470. Thecarriage has the rollers 21 which are adapted to travel in the channelsof the beams which comprise the boom 1, as shown best in Fig. 4. The

' bucket 2 is supported by' the carriage 20 through the provision ofhangers 22, and the method of attachment of the cable 11 to the carriage20 is best shown in Figs. 9 to 11. For the above purpose I provide onthe carriage 20, slidable in suitable ways or grooves 23 at oppositesides of the latter, a slide or shuttle 24. The slide or shuttle 24 hasend bars with openings 25 through which the cable 11 passes and mountedon the shuttle member 24 is a trip 26 pivoted at 2'7 and having anupwardly extending arm 28. Centrally of the slide or shuttle 24 there ismounted a slack take-up shaft 29 equipped with ratchet wheels 30 andabout which the cable 11 is wound so as to extend from the shaft in oposite directions. It will be evident that v turning the shaft 29 by theapplication of any suitable tool, any unnecessary slack in the length ofthe cable 11 may be taken up. i

The action of the trip 26 is very similar to the action of certaincorresponding trip mechanism of my previous Patent No.

1,141,470, and will be generally set forth hereinafter.

Reverse movement of the cable 11 imparts corresponding movement to thecarriage 20,-

and said carriage supports the bucket 2-for a corresponding movement ofthe latter. ,I utilize my previously invented and well known cam 31 tocooperatewith an arm 32 on. the shaft 33 for the purpose of closing thebottom door 34 of the bucket 2. The bottom door 34 is connected by linkae 35 and spring 36 with the curved link 3 which in turn is attached tothe throw over arms 38 projecting from the, shaft 33 all substantiallyas disclosed in my last named Letters Patent.

tant. The door 34 is of a length corresponding to the width of. thebucket 2, andsaid door is variably limited in its opening movement bymeans of an adjustable stop 39 which is attached to one side of thecarriage It is the adjnstability of the stop 39 which admits of theflowing of the concrete aggregates from the bucket 2 in a ribbonlikestream, the thickness of which depends upon the extent of opening ofsaid door, and due to retarding egress of the aggregates because of therestriction of the door opening. Necessarily the thickness of the streamof materials discharged from the bucket 2 determines the depth of thelayer of concrete or aggregates dispensed, so to speak, by the bucket.-The bucket opening and door 34 are advantageously arranged transverselyof the boom, and of the direction of travel of the bucket 2, for theattainment of the above result of depositing the plastic aggregates in alayer of measured thickness. The bucket'2 is designedly a low dischargebucket; in other words, the discharge end of the bucket is very near theground so as to admit of the laying down of the concrete in a relativelythin ribbon-like gravitating stream of a width .equal to the width ofthe bucket and of a depth regulated tains operative an egress opening ofa constant invariable cross section.

The boom-1 is adapted to be raised and lowered by vertical movement onan, axis established by the horizontal pivot 40 connecting the boom withthe vertical pivot 15 on the bracket 16. The means utilized for thispurpose are like those heretofore'proposed including a cable 41-attached to the upper frame work B of the machine (see- Fig. 1) passingaround a sheave 42 on the boom 1 intermediate the ends of the latter,

thence passing 'up and around another sheave 43 on the frameork'sections, down again'around a second sheave 42, co-axial thecarriage with the bucket 2, if the operator does not reverse themovement of the cable 11 by manual control of the clutches through thelever 19, said carriage will strike the knock out or shifter arm 45located adjacent to the outer end of the boom and pivoted to a bracket46 thereon. The arm ,45 is equipped with a pull rod 47 extendinglongitudinally of the boom intermediate the channels thereof. When theknock out or shifter arm 45 is. rocked upward a pull is exerted on therod 47 and said rod actuates a bell crank lever 48 near the inner end ofthe boom in such a manner as to pull downwardly upon a bar 49 which 3 isattached to another bell crank lever 50 which is pivoted at 51 on theframe work B. The vertical arm or lever 50 is connected with ahorizontal arm 52 ofistanding from the shaft 18 which it will berecalled is the controlling shaft for the shifting yokes of the clutches7 and 8. Obviously movement imparted to the bell crank lever 50 in theabove manner will shift the arm and therewith the shaft 18 to move theshaft into a position in which the clutches 7 and 8 are neutral orreversed. In this way the drive of the cable 11 is discontinued orreversed automatically through the knock out device under the initialactuation of the knock out lever 45. On inward movement ofv the carriage20, in order to automatically neutralize or render ineffective the oneof the clutches 7 or 8 which is employed to cause return movement of thecarriage upon the boom,

' there is provided a cam 53 on the carriage as seen best in Fig. 2, andthis cam is adapted to ride beneath the roller 54 on the bottom of thebar 49, thereby raising said bar and efing ope-rati'onfrom the knock outmember 45 and the principle of operation is quite similar to that .foundin my Letters Patent No..'..1,113,661 previously. referred to.

There istleft to .be .described the means for turning the' boom 1 bymovement in a horizontal plane, said means involving generally thepreviously well known worm gear sector 55 fixed on the pivot 15 by whichthe bo om is supported for said horizontal movement. This worm gear isengaged by a vworm 56 on the manually rotatable shaft 57 adapted to beturned by the wheel 58. The worm 56 may be said to be a floating worm tothe extent that it is movable endwise on the shaft 57, though-of course,splined thereto to turn therewith. The worm operates between boxes 59 inwhich the shaft 57 is journalled on the bracket 16 and springs 60 areinterposed between said boxes 59 and opposite ends of the worm. Onturning the shaft 57 to swing 'the boom 1 horizontally, the initialac'tion'of theworm-56 is to yield by compression of one of the springs60, the one in the direction inwhich the boom will turn. After slightcompression of said spring, the boom will begin to swing and the wormwill become centralized between the boxes 59 under the action of thesprings. On stoppage of the turning movement of the shaft 57, if thereis continued movement of the boom under the impetus of its swingproduced by manual operation of the wheel 58, said worm 56 will yieldlongitudinally on the shaft 57 and there will be no tendency} for thearts 55 and 56 to become locked by the iction incident to the action ofthe worm 56 as a stop for limiting the movement-or swinging of the boom.There is mounted upon the worm gear 55 a yieldable bumper 61 with whichthe carriage 20 may abut as it reaches the inward limit of'its movementin traversing the boom 1 and is automatically stopped. The bumperincludes a plate, and two springs interposed between said plate and twopivot lugs on the gear 55.

It is furthermore notable that the lever 50 controlling the reversing orclutch neutralizing action previously described is ada ted to perform anadditional function't'o t at of rendering the clutch 8 ineffective. Theoperation of this lever to' turn the shaft 18 is adapted to turn an arm62 just above the arm 52 of the shaft 18. The arm 62 is connected bylinks 63 With-the toggle lever 64 interposed between a bracket 65 on theframe work, and the free end of a brake band 66 which partiall encirclesthe clutch member 8, cooperates with the clutch 8.

Thus. it is that through the operation of'the .automatic clutchknock-out mechanism acting on the lever 50 or by the control of theshaft 18 through the hand lever 19 previbe operated to apply a brake tothe clutch 8" and thus brake the operation of the pinion 6 operating theadjacent drum 9. In this way 'quick reduction'of the movement of thedrum and corresponding stoppage of .the movement of the bucketoutwardlyandv inwardly is controlled.

The general operation of my machine according to the design hereinbeforedescribed is as follows: The bucket 2 is filled by the customary ouslydescribed,-the parts 62, 63 and 66 may no discharging of a predeterminedquantity of concrete or mixed a gregates from the mixer drum A into saiducket. The a gregates are now ready to be distributed or aid upon a thesub-grade for which urpose the operator will manually actuate t e lever19 tothrow into operation the clutch mechanism whereb to drive the drum9 in the direction to ehect an out-haul movement of the lower bight ofthe cable. The initial out-haul movement by sliding out of the shuttle24, causes the trip member 26 to assume an operative position on theouter side of the upper end of the arms 38 and continued out-haulmovement causes the carriage 20 and the bucket 2 to traverse the boom 1until the operator reverses the movement of the cable 11 b propercontrol of the clutch mechanism. in reversing the movement of the cable11 the slide or shuttle member 24 moves in the direction of the innerend of the boom, the trip member 26 actuates the throw-over arms 38,rocks the shaft 33 and releases or opens the door 34 of the bucket. Themixed aggregates in the bucket are in a free flowing date and thereversing of the cable movement is intended not only to effect openingof the door 34, but also immediate return traverse of the bucket 2relative to the boom 1. The combination of the door um and the returntraverse movement 0 the iucket 2 are important to my invention becausesuch actions together are eflective to stream the ag egates from thebucket 2 in a ribbon-like layer of substantially rectangularcross-section as previously described, the thickness or depth of whichlayer is controlled by the stop 39. As the bucket 2 returns to itsposition adixer and at the iner end jacent to the m of theboom 1, thecam 31 engages the rock arm 32, restores the throw-over arms 38 to theirelevated bucket door closing positions, and automatic sto pin of thecarna 20 and bucket 2 is e ecte through the action of the clutch'knock-out mechanism hereinbefore described, and the brake means.

If the operator fails to cause a reverse movement of the lever 19manually the effective action of the bucket discharge will begin to takeplace as the bucket reaches the outer end of the boom. This will beperformed automatically through the carriage 20 abutting with anoperating the knock-out or shifter 'arm 45 of the clutch mechanismcontrolling the drive means. Furthermore, the operation of the arm 45will be suclr as not only to render inactive the clutchcontrolling theout-haul movement of the render active the clutch whi in-haul movementof said cable whereby the movement of the bucket 2 will be actuallyreversed so as to insure the laying of theconcrete by streaming of thesame out ch causes the the cable 11 by operation of h cable, but to I ofthe bucket 2 in the manner above set forth. v

The method which I practice in the actual operation of my machine is theconveying. or conducting of the ag gates mixed in the mixer to the siteof eposit, by the distributing element or bucket of course, and thenwhile the aggregates in their plastic condition are in movement they arecaused to flow gravitatively from the bucket in a continuous stream of apredetermined depth or thickness substantially equal to that of the slabor portion of pavement of which the particular batch of the gregateswill ultimately form a part. By this method laborious work in spreadingthe materials is saved. This is a novel method of my invention. I

The action of the brake-band 8 is incident to straightening of the linksof the toggle lever 64 and takes place on both the inhaul and outhaulmovements of the bucket 2.

Whether the operation of the member '45 effects mere neutralizing of theclutchdevices requiring the reverse movement of the bucket to beeffected b manual operation, or reversing of the c utch mechanism andinhaul movement of bucket 2 depends on the adjustment of the arm 45, andthe 05 latter is controlled by adjustment of turn buckle 47" in thelength of the rod 47, or in any suitable manner.

Of course the dumping and reverse movement of bucket 2 may be performedatany lpoint in the outward movement of the ucket, as well understood onreference to my previous patents.

It is notable that as the portion 11 of the cable unwinds from thespiral groove of the drum 9, the portion 11" winds into the vacated partof the groove, and vice versa.

he ring gear construction of A is known to those versed in thisart,,being shown in my patents above identified.

e parallelism of the bucket and door travel, with the ground or.subgrade, is derived through the combinative action of the 4142-4344,the latter cothe boom 1. This parallelism of operation is veryneoessaryto maintain a uniformit of thickness of the plastic concretelai on the sub-grade by gravitation. Furthermore, the said uniformity isinsured since the boom afl'ords a track held 12 stationary by themachine structure AB which-does not travel during the laying down of theplastic ag gates.

Having thus describe nhy invention, what claim as new and desiretosecure by Reissue Letters Patent,- is

1. In a concrete distributing machine of the boom and bucket type, adistributin element, a horizontally swingin elevate support to carrythis element in spaced 1 0 4 01st means actin with us relation to theground, means for controlling delivery of 7 gravitative discharge ofmaterials to be disbinedfwith an instrumentalitg tributed,'means tocontrol the flowing of said materials by said element in a layer ofmeasured thickness when discharging, means to hold the support againstmove ment whilst the discharging takes place,

and to adjust it to cause travel of said element arallel with theground. eans as set forth in claim 1, comfor varying the thickness ofthe layer concrete deliver-ed according to predetermined requirements.

4. In a concrete distributin machine, the combination of a portablesupport stationary during distributing operations.

a boom thereon to operate over a con:

crete distributing area, a normally non discharging distributing bucketadapted to traverse said boom and having a discharge opening elongatedtransversely of its direction of traverse to form a relatively widetransverse discharge for the bucket, said opening being restricted to anarea which retards the outflow of plastic concrete and shapes the sameto causeafiow in a layer of a thickness predetermined by the opening,and operating means to bring the said opening into action .to dischargethe contents of the bucket when the latter has moved to the desiredpoint of deposit upon a sub-grade, including means to move the bucket asdischarged, whereby the concrete in the bucket is s read over an area ofrelatively lar widt as it passes from the opening to t e sub-grade.

to the ground.

11 a concrete distributing machine, a source of supply'of plasticconcrete, a distributing element, a boom from which said element issuspended, me ans to move said element over and s aced from aniarea ofdistribution to and rom said source of supply, and means to cause.materials to pass from said element in a stream-like-layer ofpredetermined thickness, said last means operating during a certainportion of the said movement of the distributing element,.

and a machine structure supporting the boom to hold it stationary whilethe.dis-'- tributing element is streaming the materials 6. In a concretedistributing machine a source of supply of plastic concrete, a istheboom and bucket type, a normally nonl I 15,7ea

tributingelement, a horizontally swingilgg boom from which said elementis suspend and spaced from; the ground, means to move said element inspaced relation to but over a surface to be paved and close to saidsurface so that materials delivered by the element may retainsubstantially the form of their delivered condition while gravitating tosaid surface, operating-means to carry the distributing element joveranarear of distribution and, to cause delivery action thereof, meansadapted to control streaming of the materials from the element in alayer of ascertained thickness during such movement, and means to adjustthe boom up and down to maintain the control'me'ans in parallelism withthe ground;

7. In a concrete distributing machine of the boom and bucket type, adistributing element, a superposed elevated support therefor upon whichit moves, means to move said element over and wholl from a surface to bepaved an spaced therefrom but close enough to said surface so thatmaterials delivered by the element may retain substantially the form oftheir delivered condition as they are deposited on the ground, means tosimultaneously cause discharge of the materials in a stream and movementof-the distributing element as the materials pass therefrom, a machine.

structure carrying the elevated support to hold it stationary as thematerials discharge, and means to adjust the support to remain arallelwith the ground to compel the said element ingly. V 4

V 8. In a concrete distributing machine of the boom and bucket type, anormally nondischarging distributing element comprising a conveyer,cable means to move'said element over a surface to be paved sothatmaterials conveyed and delivered by the element may retain substantiallythe form of their delivered condition, and means to actuate the cablemeansto simultaneously cause discharge of the materials in a stream andcause movement of the distributing element as the materials pass.therefrom,

the boom and bucket type including a" bucket distributing element havingad'ustable trip means to effect delivery 0 its contents, and meansfor'controlling delivery of plastic concrete by said element in a havenof 'measuredthickness variable by a justment of the tri means.

10. In a concrete istributing machine of spaced to move correspond-.

for controlling delivery of plastic concrete 1 element is deliveringconcrete.

the combination of a boom, a

by said element in a layer of measured thickness, and means to at apredetermined time simultaneously cause delivery action of the concretefrom said element and movement of the distributing element during suchdelivery action, an elevated horizontally swinging boom on which saidelement moves, and a machine structure supporting the boom in astationary position while the 11. In a concrete distributing machine ofthe boom and bucket type, a distributing element, and means forcontrolling delivery of plastic concrete by said element in a layer ofmeasured thickness, the distributing element comprising an openabledoor, and means to vary the degree of opening movement of the door whilespaced from the ground to thereby vary the thiclmess of the layer ofplastic material distributed through said door.

12. Ina concrete distributing machine of the boom and bucket type, adistributing element, means for controlling delivery or. plasticconcrete by said element in a layer of measured thickness, thedistributing element comprising a discharging means, and a. single meansto simultaneously render the discharging meansactive and effect bodilymovement of the distributing element in such a manner that tliefplasticmaterials stream out behind it in such movement, and a relativelstationary boom to hold the eleinent who ly spaced from the ground whiledischarging.

13. In a concrete distributing machine of the boom and bucket type, thecombination of a boom, a distributing bucket adapted to traverse saidboom propelling means' for said bucket, the bucket comprising anopenable door operable by the propelling means for regulating the flowof plastic materials from the bucket, andmeans to variably limit theopening movement of the door.

' 14. Ina concrete distributin machine, istributing bucket adapted totraverse said boom, propelling, means for said bucket, the bucketcomprising an openable door disposed substantially transverse to thedirection of propulsion of the bucket for regulating the flpw of plasticmaterials from the. bucket, and a single means whereby the doormay beopened so as to permit a retarded streaming out of the plastic materialsfrom the bucket, and the bucket may have imparted thereto simultaneousmovement to cause the contents thereof to be discharged in a ribbon-likemanner.

15.- In a boom and bucket concrete distributing means, in combination, aboom, a bucket to traverse the boom'and equipped with a dischargeopening,'driving means for causing the traversing movement of the bucketon the boom, means to restrictively ren'der operative the dischargeopening, so that the contents of the bucket willstream therefrom in aretarded manner, and means for causing the driving means to move thebucket over a distributing area after said opening of the bucket becomesoperative, the bucket being arranged'so that its discharge opening isnear the surface on which the contents of the bucket are to be depositedwhereby the bucket contents stream to the surface in a relatively fiatlayer.

16. In concrete distributing means, in combination, a boom, avbucket totraverse the boom, :1 discharging door for said bucket, and anadjustable stop controlling the degree of opening movement of said door.I

17. In concrete distributing means, in

combination, a boom, a bucket to traverse the boom, a discharging doorfor said bucket, an adjustable stop controlling'the degree of openingmovement of said door, door opening trip mechanism connected with thedoor and cooperative with said stop, and means for moving the bucket.

18. In concrete distributing means, in combination, a boom, a bucketarranged to traverse the boom, a carriage supporting said bucket on theboom, the bucket being formed with an inclined bottom and having adischarge door operating close to the surface to which materials are tobe discharged from the bucket, but held spaced therefrom.

both when closed and open, and means to simultaneously open thedischarge door of the bucket and impart movement to the latter to causethe contents ofthe same to stream ast said door in a layer ofpredetermined thickness, and a frame supporting the boom to hold itstationary while the bucket is discharging.

19. In a concrete distributing machine. the combination 'of a boom, abucket adapted to traverse theboom, driving mechanism for the bucket, adoor for the bucket supported I so as to remain spaced from the groundboth 7 when closed and open, ;-"means to control opening of the door toa predetermined position to regulate the thickness of the mate rialsdischarged from the bucket, means to drive the bucket in one directionalong, the boom, means ,to automatically reverse the movement of thebucket upon said boom. and for simultaneously opening the door of thebucket .Whereby the combined opening of said door, its arrangement inthe bucket and the movement of the bucket will cause the contents of thelatter to stream from the bucket in a ribbon-like'layer of predeterminedthickness, a'frame to support the boom, and adjusting means between theconcrete.

boom and frame to insure travel of the bucket parallel with the groundin laying 20. A machine substantially as claimed in claim 19, combinedwith a control device for variably limiting the openin movement of thedoor of the bucket, wher iy to admit of changing the thickness of thelayer of materials discharged from the bucket.

21. In a concrete distributing machine,

the combination with a boom shiftable overin a layer-like form, thedistributing ele-' ment being freely movable back and forth upon theboom'from the supply means to a point of distribution,and means to causedischarge action of the distributing element to stream'the concretethrough its opening in a layer of measured thickness to thus avoidlaborious spreading work necessary were the contents .of thedistributing 'element dumped upon the sub-grade en masse,

a frame to support the boom, and adjusting means between the boom andframe to insure travel of the bucket parallel with the ground in layingconcrete. 7,

22. In a concrete paving machine, in combination, a portable support, aboom movable on said support over an area of distribution, a conveyingreceptacle adapted to traverse the boom from a place in which itreceives concrete to a place for discharge thereof, said receptaclebeing constructed so that the concrete in plastic state may readilygravitate therefrom, but being normally in a non-discharging condition,so that its contents may be retained until a desired time of discharge,the receptacle having discharging equipment enabling its'contents tofreely flow therefrom in a streamed out layer, means for renderin thedischarging equipment operative, an to move the receptacle at the sametime to lay the concrete over a sub-grade area of considerable extent,while said discharging equi ment remains operative, thereby to avoilaborious spreading work respecting the distributed concrete, and meansto restore the receptacle to its normal non-discharging conditlon.

23. A concrete paver substantially as claimed in claim 22, combined withadjustthe means to move the receptacle during the I discharging actionis such that the contents of the receptacle discharges therefrom in adirection opposite that in which the receptacle is moving.

25. In a boom and bucket type concretedistributer machine, a boom, apower operating bucket arranged to traverse said boom',

comprising a discharge opening, means re-' strictively controllingegress of'the contents of the receptacle from the said opening, as

the receptacle moves, so that said contents" are retarded and caused tobecome deposited. upon a road surface in a layer of measured thickness,said egress control means being spaced from the road surface whendischarglng, and means to maintain the boom substantially parallel withthe road surface irrespective of the inclination of the latter to causethe egress means to travel in a path parallel with said surface.

26. In'a concrete distributing machine of the boom and bucket type, thecombination of a relatively stationary machine structure carrying thesupply ofconcrete, a rearwardly extending boom pivoted at its front endto the machine structure and adapted to have its rear end raised andlowered to maintain the boom in parallelism with the subgrade upon whichthe concrete is to be distributed, a distributing bucket adapted totraverse said boom and to receive concrete from the source of supplywhile 1n position at the front end of the boom, said bucket having atranverse discharge opening, an adjustable door controllin said openingwhereby the concrete may caused to flow by gravity from the bucket andbe-deliveredupon the sub rade in a wide stream of redetermined t icknessduring the trave of the bucket in a direction toward one end of theboom, and power operated means common to the buc for traversing thebucket lengthwise of the boom and opening and closing the door.

ThiS'SPBOIfiOfltiOII signed the 6th day of- Nov., 1923, at Milwaukee,Wisconsin.

ERICH H. ,LICHTENBERG.

et and its adjustable door

